Throttle check valve



Jan. 16, 1968 B. c. BENJAMIN 3,363,890

THROTTLE CHECK VALVE Filed Oct. 18, 1965 THROTTLE CGNTROL SHAFT VACUUMFROI$ INTAKE MANIFQLD OPENED (CLOSED 2 F I6. I

33 3a 5 39 Z7 28 3/ J3 \x A W mumuw 36 5s /2 INVENTOR. F a 3 BENJAMIN C.BENJAMIN ATTORNEYS United States Patent Ofiice 3,363,890 Patented Jan.16, 1968 3,363,890 THROTTLE QHECK VALVE Benjamin C. Benjamin, Flint,Mich, assignor to Fuller Emerson Manufacturing Company, Detroit, Mich, acorporation of Michigan Filed Oct. 18, 1965, Ser. No. 497,199 14(Iiaims. (Cl. 2671) ABSTRACT OF THE DISCLOSURE The throttle check valvedisclosed herein comprises a casing including a diaphragm dividing theeasing into two chambers. The casing has an opening in one wallcommunicating with one chamber and a spring is positioned in the onechamber and acts on the diaphragm to yieldingly urge the diaphragm awayfrom the opening. A shaft is fastened to the diaphragm and extendsthrough the other chamber in a wall of the casing and has an openingtherethrough providing communication between the end of the shaft andthe first-mentioned chamber. The shaft has a valve seat on the endthereof and a cap is provided surrounding the end of the shaft and has aseal adapted to engage the valve seat. A spring yieldingly urges the capaway from the seat and interengaging means between the cap and the shaftlimit the axial outward movement of the cap due to the action of thespring.

This invention relates to valves and particularly to valves for checkingor retarding the movement of the throttle of a carburetor on an engineof an automotive vehicle to a closed position.

It has long been known that in automotive vehicles having highcompression engines, a sudden closing of the throttle after a suddenacceleration results generally in stalling of the engine. Accordingly,it has been heretofore suggested to provide means for retarding thereturn of the throttle by a check valve that is connected to vacuum andis operable upon lifting the foot from the throttle pedal to provide aretarding force on the return of the throttle to closed position.

It is an object of this invention to providea throttle check valve thatis particularly adapted for use in retarding the return of a throttle toclosed position which is ellectively protected against dirt and the likeand which is low in cost.

In the drawings:

FIG. 1 is a partly diagrammatic side view of a valve embodying theinvention.

FIG. 2 is a longitudinal sectional view through the valve shown in FIG.1.

FIG. 3 is a fragmentary view of a portion of the valve shown in FIGS. 1and 2, showing the parts in a different operative position.

FIG. 4 is an end view of a cap utilized in the valve.

Referring to FIG. 1, the valve embodying the invention is adapted to beutilized in connection with a throttle linkage that includes a lever 11which moves with the throttle valve on an engine of an automotivevehicle. In accordance with conventional linkage of a throttle, thelever 11 moves from the solid line position shown in FIG. 1 to thedotted line position when the operator lifts his foot off the throttlepedal. At the same time, the throttle is returning to a closed position.

As shown in FIG. 1, the valve 10 is adapted to be mounted on a bracket12 and is connected by a flexible line 13 to vacuum from the intakemanifold.

Referring to FIG. 2, the valve 10 comprises a casing 14 consisting oftwo sheet metal halves 15, 16 having peripheral flanges 17, 18 betweenwhich. a diaphragm 19 is interposed. The flange 17 of the casing half 15is bent over as at 23 to clamp the diaphragm. in position and providetwo chambers 21, 22.

The casing half 16 is provided with an orifice 23 that in turn providescommunication to the interior of a tubular fitting 24 which is welded onthe casing half 16 and onto which the tubing 13 is mounted.

As shown in FIG. 2, washers or discs 25, 26 are pro vided on each sideof the diaphragm and serve as a mounting for an axially movable shaft orstem 27 that is journalled in a bearing 28 fixed to the casing half 16.A coil spring 29 is interposed between the washer 26 and a sheet metalretainer ring 30 to yieldingly urge the diaphragm 19 away from theorifice 23 and force washer 25 against the wall of the casing half 15. Afilter element 31 of foraminous material is clamped by the ring 30against the wall of the casing half 16.

The shaft or stem 27 is provided with an axial opening 32 that providescommunication between the chamber 22 and the outer end of the shaft 27.The outer end of the the shaft 27. A flat resilient gasket 38 of cork orrubber is surface 34. A cap 35 of plastic, such as nylon, is provided onthe end of a shaft 27 and includes a base 36 and a circumferential skirtor flange 37 that surrounds the end of the shaft 27. A fiat resilientgasket 38 of cork or rubber is provided on the inner surface of the base36 and is adapted to seal against the sealing surface 34 when the cap 35moves inwardly.

The outermost portion of the opening 32 is enlarged in diameter as at 39and a coil compression spring 40 is interposed between a shoulder 41that is formed in the end of the shaft 35 and the base 36 of the cap toyieldingly urge the cap 35 outwardly. To limit the outward movement ofcap 35, the outer diameter of the shaft 27 is reduced adjacent the endto form a shoulder 42 and radially inwardly extending projections 43(FIGS. 2, 3 and 4) are provided on the cap 35 which engage the shoulder42 and limit the axial outward movement of the cap 35. It can be seenthat in FIG. 4 the flanges 43 are separated by axial passages 44 thatpermit free communication of air as is required during normal operation.The skirt 37 functions to prevent the entry of dirt and also as a guidefor the base 36 as it is moved toward the sealing surface 34 to providea seal even under eccentric load.

When the throttle pedal is depressed and the lever 11 is moved away fromthe cap 35, the application of vacuum through tubing 13 and orifice 23continuously draws air through passage 32 and between the skirt of thecap 35 through axial passage 44 and through the axial opening 32.However, when the operator lifts his foot 011? the throttle pedal, thelever 11 immediately returns by spring linkage forming a part of thethrottle linkage to a position where it engages the cap 35. This movesthe cap 35 against the action of spring 40 to bring the gasket 38against the seat 34 of the shaft 27 as shown in FIG. 3.

Thereafter, the application of vacuum from the manifold tends to slowlyevacuate the chamber 22. This evacuation is retarded primarily by theorifice 23 and secondarily by the spring 29 thereby providing a forcewhich opposes the return of the lever 11 to a position corresponding tothe throttle closed position. However, as vacuum continues, the chamber22 is finally evacuated sufliciently to permit the diaphragm 19 and, inturn, the shaft 27 to move to the right as shown in FIGS. 2 and 3 and,in turn, permit the lever 11 and associated linkage connected to thethrottle to move to the dotted line position shown in FIG. 1.

When the throttle is again depressed, the lever 11 is moved away fromthe end of the cap permitting the spring to move the cap 35 away fromthe end of the shaft 27. The return spring 29 then forces diaphragm 19and shaft 27 to their original positions.

It can thus be seen that there has been provided a throttle check valvewhich effectively retards the closing of the throttle, which is notsusceptible to dirt and the like because the valve seat is entirelyprotected by the flange 37 and which is relatively low in cost.

I claim:

1. A throttle check valve comprising a casing,

piston means in the casing separating the casing into two chambers,

an opening associated with one of said chambers for applying a reducedpressure to said chamber,

orifice means associated with said opening,

spring means yieldingly urging said piston means away from said opening,

a shaft connected to said piston means and extending through said otherchamber,

a passage through said shaft providing communication between the end ofsaid shaft and said first-mentioned chamber,

a valve seat on the end of said shaft,

a cap surrounding the end of said shaft and having a seal thereon forengaging said valve seat,

means yieldingly urging said cap away from said valve seat,

and means for retaining said cap on the end of said shaft and limitingthe outward movement of said cap under the action of said yieldingmeans' 2. The combination set forth in claim 1 wherein said capretaining means comprises a shoulder spaced from the end of said shaft,

and radially inwardly extending flanges on said cap engaging saidshoulder.

3. The combination set forth in claim 2 wherein said cap is made ofplastic material.

4. The combination set forth in claim 2 wherein said cap is made ofnylon.

'5. The combination set forth in claim 1 including a filter interposedbetween said first-mentioned chamber and the opening through saidchamber in advance of said orifice means.

6. A throttle check valve comprising a casing,

a diaphragm dividing said casing into two chambers,

said casing having an opening in one wall communicating with one saidchamber,

spring means positioned in said one chamber and acting on said diaphragmto yieldingly urge said diaphragm away from said opening,

a shaft fastened to said diaphragm and extending through said otherchamber and a wall of said casing,

said shaft having an opening therethrough providing communicationbetween the end of said shaft and said first-mentioned chamber,

said shaft having a valve seat on the end thereof,

a cap surrounding the end of said shaft,

said cap having a seal adapted to engage said valve seat,

means yieldingly urging said cap away from said seat,

interengaging means between said cap and said shaft limiting the axialoutward movement of said cap on said shaft due to the action of saidyielding means.

7. The combination set forth in claim 6 wherein said yielding meanscomprises a coil spring,

said shaft having an axial opening therein,

said coil spring being interposed between said cap and the base of saidaxial opening in said shaft.

8. The combination set forth in claim 6 wherein said interengaging meanscomprises a shoulder spaced from the end of said shaft,

and inwardly extending projections on said cap engaging said shoulder.

9. The combination set forth in claim 6 wherein said cap has acontinuous peripheral skirt extending axially of said stem andsurrounding the end of said stem.

10. The combination set forth in claim 6 including orifice meansassociated with said opening in said wall of said casing.

11. A throttle check valve comprising a casing,

piston means in the casing separating the casing into two chambers,

an opening associated with one of said chambers for applying a reducedpressure to said chamber,

orifice means associated with said opening,

spring means yieldingly urging said piston means away from said opening,

a shaft connected to said piston means and extending through said otherchamber,

a passage through said shaft providing communication between the end ofsaid shaft and said firstmentioned chamber,

a valve seat on the end of said shaft,

a cap surrounding the end of said shaft and having a seal thereon forengaging said valve seat,

means yieldingly urging said cap away from said valve seat,

said shaft having a shoulder spaced from the end thereof,

said cap having radially inwardly extending flanges engaging saidshoulder and limiting the outward movement of said cap under the actionof said yielding means.

12. A throttle check valve comprising a sheet metal casing comprisingtwo halves,

a diaphragm interposed between said halves and dividing said easing intotwo chambers,

said casing having an opening in one half communicating with one saidchamber,

a tubular fitting mounted in said opening,

a coil spring interposed between said one half and said diaphragm andyieldingly urging said diaphragm away from said opening,

a bearing on said other half,

a shaft fastened to said diaphragm and extending through said otherchamber and said bearing,

said shaft having an opening therethrough providing communicationbetween the end of said shaft and said first-mentioned chamber,

said shaft having a valve seat on the end thereof,

a cap surrounding the end of said shaft,

said cap having a seal adapted to engage said valve seat,

spring means yieldingly urging said cap away from said seal,

interengaging means between said cap and said shaft limiting the axialoutward movement of said cap on said shaft due to the action of saidyielding means.

13. The combination set forth in claim 12 wherein said spring meanscomprises a coil spring,

said shaft having an axial opening therein,

said coil spring being interposed between said cap and the base of saidaxial opening in said shaft.

14. The combination set forth in claim 12 wherein said cap has acontinuous peripheral skirt extending axially of said stem andsurrounding the end of said stern,

said interengaging means comprises a shoulder spaced from the end ofsaid shaft,

and inwardly extending projections on said skirt of said cap engagingsaid shoulder.

6 References Cited UNITED STATES PATENTS 2,657,037 10/1953 Braun 267-13,287,007 11/1966 Schoeppach 267-1 ARTHUR L. LA POINT, Primary Examiner.EUGENE G. BOTZ, Examiner.

R. M. WOHDFART H, Assistant Examiner.

